sctp: Add ASCONF operation on the single-homed host

In this case, the SCTP association transmits an ASCONF packet
including addition of the new IP address and deletion of the old
address.  This patch implements this functionality.
In this case, the ASCONF chunk is added to the beginning of the
queue, because the other chunks cannot be transmitted in this state.

Signed-off-by: Michio Honda <micchie@sfc.wide.ad.jp>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Acked-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index cd8c929..31d7ea2 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1913,6 +1913,8 @@
 	 * after reaching 4294967295.
 	 */
 	__u32 addip_serial;
+	union sctp_addr *asconf_addr_del_pending;
+	int src_out_of_asoc_ok;
 
 	/* SCTP AUTH: list of the endpoint shared keys.  These
 	 * keys are provided out of band by the user applicaton